E.g. "MatthewWheeler and 4 others replied to topic Re: Speed issues BT (PlusNet) exchange kit VS Talk..."
The link is to the last post (by Matthew) which means you have to look back to find the first unread post.
It should either go to the the post by the first of the 4 others, or the first unread post in the topic.
This was raised two years ago in a topic raised primarily about something else (https://community.plus.net/t5/Community-Site-Feedback/Problem-with-forum-quot-Notification-feed-quot...) but the discussion petered out with no resolution.